There exist applications that enable users to learn what is happening around them, but the applications are predominantly for business needs such as advertisements, coupons, and so on. However, the users have to actively open an application to look for this information. For example, a user X would like to know when user Y, with something that might be of interest to user X, is near. However, both user X and user Y change their locations constantly. When both user X and user Y are in the same area, user X, who has the interest, would like to be actively notified of the interest and then decide how to act. However, such capabilities are lacking in conventional architectures.